Marginal Accuracy of Fully Contoured Zirconia Veneer With Two Preparation Designs

Abstract

Aim: The purpose of this study is to evaluate the marginal accuracy of fully contoured zirconia laminate veneer utilizing two preparation designs; butt joint incisal reduction and incisal chamfer with palatal over lab. Subjects and Methods: fortyeight maxillary central incisors were prepared into two designs in relation to incisal finish line of laminate preparation; butt joint incisal reduction and incisal chamfer with palatal over lab. Half of samples were restored with pressable lithium disilicate (e.max) as control group, and the other half were restored with fully contoured translucent machinable zirconia (Bruxzair). All laminates were cemented with resin cement and the marginal accuracy were measured. Results: With butt-joint margin design; it was found that e.max group recorded statistically significant higher marginal gap mean value (63.54±1.8 µm) than translucent Zirconia group (57.19±8.4 µm) as indicated by unpaired t-test (t value=2.6, P=0.0179<0.05) .With overlap margin design; it was found that e.max group recorded statistically significant higher marginal gap mean value (73.46±11.2 µm) than translucent Zirconia group (64.58±5.1 µm) as indicated by unpaired t-test (t value=2.5, P=0.0203 < 0.05). Conclusion: The marginal accuracy of the fully contoured zirconia veneer showed high adaptation supporting its usage for laminate veneer fabrication.